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Table 3 Association between vitamin D status in pregnancy with birth size and pregnancy loss (adjusted logistic regression analysis)

From: Trajectory of vitamin D status during pregnancy in relation to neonatal birth size and fetal survival: a prospective cohort study

  Small for gestational agea Preterm delivery (< 37 weeks)b Low birth weight (< 2500 g)c Pregnancy lossd
  OR CI 95% OR CI 95% OR CI 95% OR CI 95%
T1 25OHDe
 Continuous nmol/L 1.003 0.99–1.01 0.996 0.99–1.01 0.999 0.99–1.01 0.989* 0.98–1.00
  < 30 (ref) 1.0   1.0   1.0   1.0  
  30–49.9 1.078 0.44–2.66 1.647 0.63–4.33 2.549 0.88–7.38 1.030 0.44–2.41
  50–74.9 1.632 0.69–3.85 1.260 0.47–3.36 2.287 0.77–6.83 0.688 0.29–1.62
  75–99-9 1.292 0.51–3.27 1.332 0.48–3.73 1.665 0.51–5.49 0.809 0.33–1.96
  ≥ 100 1.294 0.38–4.42 0.502 0.09–2.72 1.255 0.22–7.27 0.000f  
T3 25OHDe
  < 30 (ref) 1.0   1.0   1.0    
  30–49.9 0.771 0.34–1.75 0.302 0.08–1.14 0.071* 0.01–0.63   
  50–74.9 0.623 0.27–1.45 0.933 0.31–2.79 0.584 0.17–1.98   
  75–99-9 0.657 0.27–1.61 0.614 0.18–2.14 0.237 0.06–1.01   
  ≥ 100 0.318* 0.11–0.90 0.446 0.11–1.76 0.215* 0.05–0.97   
Δ25OHDg
  Large increase (≥ 30 nmol/L) (ref) 1.0   1.0   1.0    
  Small increase (0–30 nmol/L) 2.564* 1.16–5.67 2.905* 1.01–8.34 3.122 0.97–10.09   
  Decrease (< 0 nmol/L) 3.679** 1.60–8.44 2.894 0.95–8.85 4.722* 1.37–16.28   
  1. T1 first trimester, T3 third trimester, 25OHD 25-hydroxyvitamin D
  2. *p < 0.05 **p < 0.01
  3. aModels include 92 (T1) and 80 (T3 and Δ25OHD) cases of small for gestational age
  4. bModels include 77 (T1) and 43 (T3 and Δ25OHD) cases of preterm delivery
  5. cModels include 57 (T1) and 31 (T3 and Δ25OHD) cases of low birth weight
  6. dModels include 96 cases of pregnancy loss
  7. eAdjusted for education, origin, season of conception and BMI at T1. Pregnancy loss models are also adjusted for gestational age at registration for antenatal care
  8. fNo case of pregnancy loss in category
  9. gAdjusted for education, origin, season of conception, BMI at T1 and 25OHD at T1